Atomic and Structure and Isotopes
(MCQ)
1. Which ion has a different number of electrons from the other three ions?
A Ga+
B CI
C
D Ca2+
[1]
Your answer
2. Which row shows the atomic structure of 37CH?
protons neutrons electrons
A 17 8 20
B 17 20 18
18 17
20 17 21
Your answer
[1]
3. How many electrons
A
B
C.
D
10
12
14
22
are in a
Na
Your answer
[1]
4. Information abouttwo isotopes of an element is given in the table.
Isotope Mass number % Abundance
A 144 24
B 145
Which statement is correct?
A. The relative atomic mass of the element is 47.61.
B. Isotope B has more protons than isotope A.
C. Isotope B has fewer neutrons than isotope A.
D. The relative isotopic mass of isotope B is 145.
Your answer
END OF QUESTION PAPER
Atomic Structure and lsotopes
1. This question is about the properties and reactions of the Group 2 element strontium.
The relative atomic mass of strontium can be determined using a mass spectrometer.
Explain what is meant by the term relative atomic mass of an element.
A sample of strontium has a relative atomic mass of 87.73.
ii.
The sample consists of:
82.9% Sr-88
6.9% Sr-87
one other isotope.
Determine the other isotope of strontium in the sample.
isotope of strontium = (21
2(a). This question is about atomic structure and the compounds of calcium, nitrogen and oxygen.
Most elements contain different isotopes.
State two differences between isotopes of the same element.
(b). Complete the table for an atom and an ion of two different elements.
Element Mass number Protons Neutrons Electrons Charge
***********... ******** 26 28 ***************** 0
80 36
[2]
3 This question is about elements from the p-block of the periodic table.
Silicon exists as a mixture of three isotopes, 28Si, 29Si and 30Si.
Complete the table to show the atomic structure of 30Si.
Protons Neutrons Electrons
30Si
[1]
A sample of silicon is analysed by mass spectrometry.
ii.
The mass spectrum shows peaks with the relative abundances below.
28Si 92.23%
29S 4.68%
30S 3.09%
Calculate the relative atomic mass of silicon in the sample.
Give your answer to two decimal places.
relative atomic mass
(2]
This question is about elements from the s-block and p-block of the periodic table.
A sample of magnesium is analysed by mass spectrometry.The mass spectrum is shown below.
78.99%
relative
abundance
(%)
10.00% 11.01%
21 23 24 25 26 27 28 29
mlz
The species causing the peaks in the mass spectrum are 1+ ions of magnesium.
Complete the table to show the number of protons, neutrons and electrons in each 1+
ion of magnesium.
mlz protons neutrons electrons
24
25
26
i. Calculate the relative atomic mass of the magnesium in the sample.
Give your answer to two decimal places.
relative atomic mass =. .......(2]
5(a). A twenty pence coin contains copper and nickel.
Copper and nickel each exist as a mixture of isotopes.
State the similarities and differences between the atomic structure of isotopes of the same element.
Similarities
Differences.
[2]
(b). The copper used to make a batch of coins is analysed by mass spectrometry. The mass spectrum is
shown below.
69.17%
relative
abundance
(%)
30.83%
60 61 62 6 64 65 67 68
mlz
Calculate the relative atomic mass of the copper used to make the coins.
Give your answer to two decimal places.
relative atomic mass : [21
One coin has a mass of 5.00 g and contains 84.0% of copper, by mass.
ii.
Calculate the number of copper atoms in one coin.
Give your answer in standard form and to three significant figures.
number of copper atoms [21
6. A sample of zinc was found to contain four isotopes with the abundances shown in the table.
Isotope Abundance (%)
64Zn 49.0
667n 27.9
67Zn 4.3
68Zn 18.8
Define the term relative atomic mass.
[31
Calculate the relative atomic mass of zinc in this sample.
Give your answer to two decimal places.
relative atomic mass of zinc : (2]
7 Nitrogen is the most common gas in the atmosphere.
Atoms of nitrogen consist of protons, neutrons and electrons.
Complete the table below.
Position within the
Particle Relative mass Relative charge
atom
Proton
Neutron
Electron shell
[21
8. Bromine has two isotopes, Br-79 and Br-81. The relative atomic mass of bromine is 79.9.
Calculate the percentage of Br-79 atoms in a sample of bromine.
Answer = % [2]
9 This question is about the elements with atomic numbers between 58 and 70.
Cerium, atomic number 58, is a metal.
Completethe table to show the relative charge of each particle and the number of each particle
found in a 140Ce2+ ion.
Particle
Relative charge of each Number of each particle
particle present in a 140Ce* ion
proton
neutron
electron
[2]
10(a). Antimony, Sb, has atomic number 51.
Antimony exists as a mixture of isotopes.
What is meant by the term isotopes?
Different isotopes of antimony have the samechemical properties.
Explain why.
Complete the table below to show the atomic structure of 121Sb.
Protons Neutrons Electrons
[1]
(b) The relative atomic mass of antimony is 121.8.
Define the term relative atomic mass.
[31
A sample of antimony, A, = 121.8, was analysed and was found to consist of 60% 121Sb
and one other is otope.
Determine the mass number of the other isotope in the sample of antimony.
mass number of the other antimony isotope [1]
=
11. Bromine and mercury are the only two naturally occurring elements that are liquids at room temperature and
pressure. Some physical properties of these two elements are given below.
Electrical
Appearance at
Melting point /°C Boiling point/°C conductivity of
room temperature
the liquid
Bromine dark orange liquid -7.2 58.8 very low
Mercury shiny silver liquid -38.8 356.7 good
Element X melts at temperatures reached on very hot summer days.
A sample of element X was analysed by mass spectrometry. The mass spectrum is shown below.
72.17%
relative
abundance
(%)
27.83%
85 87
mlz
Calculate the relative atomic mass of element X.
Give your answer to two decimal places.
relative atomic mass 21
Suggest the identity of element X.
i
[1]
12(a). Europium, atomic number 63, has two isotopes, 151Eu and 153Eu.
Complete the table to show the number of protons, neutrons and electrons in the 153Eu3+ ion of
europium.
protons neutrons electrons
153Eu3+
[1]
(b) Atoms of europium have electrons in orbitals within the first five shells. The first three shells of
europium are full,
Complete the table to show the number of electrons in the following regions of a europium atom.
number of
electrons
the 1s sub-shell
a 3p orbital
the 3rd shell
[3]
END OF QUESTION PAPER
